1. Field of the Invention
The present invention relates to magnetic valves. More particularly the invention relates to an insulating insert for magnetic air valves. Such find use in control systems of railroad locomotives.
2. Description of the Related Art
Magnetic air valves, also known as magnet valves, solenoid valves, and electric air valves, are generally well known in the art. Typically such valves and valve assemblies comprise a magnetically energizable core encased in a metal housing having an open front end and a closed rear end. The metal housing usually has an upper front hole having a removable strain relief wire connector or hollow bolt attached therethrough. The such wire connectors typically house wires for actuating the magnetic core inside the housing.
With such magnetic valves, air flow typically occurs only when certain spool valves are open. A plunger, actuated by the magnetic core, is supported in a bore through both the rear of the metal housing and through the magnetic core. The plunger cooperates with a spool valve member to shift the spool valve member upon energizing of the magnetic core from an open to a closed position, or vice versa, as desired. Such valves are commonly used in locomotive control systems.
The problem to be solved is that during actuation of the valve, there are rapidly succeeding shock movements that may vibrate the magnetic valves and the wires therein. With vibration over time, the wires may fray and/or come into contact with the metal walls of the magnetic valve housing, thus shorting out the valve, tripping a control breaker, and shutting down the locomotive.
It would therefore be desirable to provide a device for minimizing electrical contact between the wires and the metal housing of the magnetic valve. The present invention provides a solution to this problem.
The invention comprises an insulating insert for separating wires from an inside metal wall of the magnetic valve housing. The insert comprises an electrically insulating sleeve having side walls, top and bottom opposite open ends, and a threaded bushing attached around a hole through one side wall of the sleeve. The bushing engages a removable, hollow, strain relief wire connector or hollow bolt of the magnetic valve, which wire connector contains wires running into the housing to form the requisite electrical connections with the magnetic core of the valve. The insert also preferably includes an insulating flange around the perimeter of the top open end of the sleeve to thereby further insulate the housing, and to provide a seal between the housing and an optional covering.
The invention provides an insulating insert for a magnetic valve which comprises:
a) a hollow, electrically insulating sleeve having sidewalls defining a top open end and a bottom open end opposite to the top open end; one of the side walls having a circular hole therethrough; and
b) a threaded bushing fixedly attached to the sidewall around the circular hole.
The invention further provides an insulating insert for a magnetic valve which comprises:
a) a hollow, electrically insulating sleeve having sidewalls defining a top open end and a bottom open end opposite to the top open end; one of the side walls having a circular hole therethrough;
b) a threaded bushing fixedly attached to the sidewall around the circular hole;
c) an electrically insulating flange around a perimeter of the top open end, which flange projects substantially perpendicularly to said sidewalls, and which flange comprises a pair of opposing fastening holes therethrough; and
d) an electrically insulating covering in contact with the flange around the perimeter of the top open end of the sleeve.
The invention still further provides a magnetic valve assembly which comprises:
a) a magnetic valve comprising:
i) a metal housing having a top open end and a bottom closed end, an upper front hole through a front side of the metal housing near the top open end, and two opposing lower holes through opposite front and back sides of the metal housing near the bottom closed end;
ii) a magnetic core having conductive connectors, and a central bore therethrough, which magnetic core is positioned within the bottom closed end of the metal housing such that the conductive connectors face in a direction towards the top open end of the metal housing, and that the central bore of the magnetic core is concentrically aligned with the two opposing lower holes through the opposite front and back sides of the metal housing;
iii) a removable strain relief wire connector positioned through the upper front hole in the metal housing; and
iv) conductive wires electrically attached to the conductive connectors of the magnetic core within the metal housing of the valve, which wires run through the wire connector and out of the magnetic valve; and
b) an insulating insert comprising:
i) a hollow, electrically insulating sleeve having sidewalls defining a top open end and a bottom open end opposite to the top open end; one of the side walls having a circular hole therethrough; and
ii) a threaded bushing fixedly attached to the sidewall around the circular hole;
which insert is positioned within the top open end of the magnetic valve such that the sidewalls of the electrically insulating sleeve are in contact with an inside surface of the metal housing, the strain relief wire connector engages the threaded bushing of the insulating insert within the magnetic valve such that a first end of the wire connector extends into the metal housing while a second end of the wire connector remains outside of the housing, and the conductive wires of the magnetic valve run from the conductive contacts, into the bottom open end of the insulating insert, through the wire connector, and out of the magnetic valve.
The invention still further provides a process for electrically insulating a magnetic valve which comprises:
a) providing a magnetic valve comprising:
i) a metal housing having a top open end and a bottom closed end, an upper front hole through a front side of the metal housing near the top open end, and two opposing lower holes through opposite front and back sides of the metal housing near the bottom closed end;
ii) a magnetic core having conductive connectors, and a central bore therethrough, which magnetic core is positioned within the bottom closed end of the metal housing such that the conductive connectors face in a direction towards the top open end of the metal housing, and that the central bore of the magnetic core is concentrically aligned with the two opposing lower holes through the opposite front and back sides of the metal housing;
iii) a removable strain relief wire connector positioned through the upper front hole in the metal housing; and
iv) conductive wires electrically attached to the conductive connectors of the magnetic core within the metal housing of the valve, which wires run through the wire connector and out of the magnetic valve; and
b) providing an insulating insert which comprises:
i) a hollow, electrically insulating sleeve having sidewalls defining a top open end and a bottom open end opposite to the top open end; one of the side walls having a circular hole therethrough; and
ii) a threaded bushing fixedly attached to the sidewall around the circular hole; and
c) positioning the insulating insert within the top open end of the magnetic valve such that the sidewalls of the electrically insulating sleeve are in contact with an inside surface of the metal housing, the strain relief wire connector engages the threaded bushing of the insulating insert within the magnetic valve such that a first end of the wire connector extends into the metal housing while a second end of the wire connector remains outside of the housing, and the conductive wires of the magnetic valve run from the conductive contacts, into the bottom open end of the insulating insert, through the wire connector, and out of the magnetic valve.